Security Hardening

How to Install Zabbix on RHEL 8 — step-by-step RHEL 8 tutorial on Progressive Robot

How to Install Zabbix on RHEL 8

Zabbix is a mature, enterprise-grade open-source monitoring platform capable of tracking availability, performance, and log data for thousands of hosts from a single server. It ships with auto-discovery, customizable triggers, rich alerting integrations, and a polished web interface. Installing Zabbix 6.x on RHEL 8 takes roughly thirty minutes and gives you production-ready monitoring backed by […]

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Common Problems 121554

Debian 9 – cron jobs stop running due to anacron or timer overlap

🟡 Medium   ⏱ 5–30 min  Last verified: 6 June 2019 Affected versions: Debian 9 📖 ~1 min read Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution – Primary Fix Solution – Alternative Approaches Verification & Acceptance Criteria Rollback Plan Prevention & Hardening Related Errors & […]

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Common Problems 117999

Ubuntu 18.04 LTS Failed to Fetch Repository Metadata

🟡 Medium   ⏱ 5–30 min  Last verified: 6 June 2019 Affected versions: 18.04 LTS 📖 ~1 min read Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution – Primary Fix Solution – Alternative Approaches Verification & Acceptance Criteria Rollback Plan Prevention & Hardening Related Errors & […]

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Common Problems 112539

Windows Server 2019 — SMB signing mismatch causes slow file transfers — Fix & Prevention

🟡 Medium   ⏱ 5–30 min  Last verified: 6 June 2019 Affected versions: Windows Server 2019 📖 ~1 min read Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution — Primary Fix Solution — Alternative Approaches Verification & Acceptance Criteria Rollback Plan Prevention & Hardening Related Errors […]

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Amazon Linux 2 — evince — multiple vulnerabilities (2 CVEs) — patch and remediation guide — diagnosis and fix on Amazon Linux 2

Amazon Linux 2 — evince — multiple vulnerabilities (2 CVEs) — patch and remediation guide

🟢 Low   ⏱ 5–15 min  Last verified: 25 May 2026 Affected versions: Amazon Linux 2 📖 ~4 min read  •  Source: Amazon Linux advisory ALAS2-2020-1511 Related CVEs: CVE-2019-14494 CVE-2019-11459 Upstream summary: A divide-by-zero error was found in the way Poppler handled certain PDF files. A remote attacker could exploit this flaw by providing a […]

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FreeBSD 12 — openvpn-polarssl — multiple vulnerabilities (8 CVEs) — patch and remediation guide — diagnosis and fix on FreeBSD 12

FreeBSD 12 — openvpn-polarssl — multiple vulnerabilities (8 CVEs) — patch and remediation guide

🟡 Medium   ⏱ 10–30 min  Last verified: 6 June 2019 Affected versions: FreeBSD 12 📖 ~4 min read  •  Source: FreeBSD VuXML VuXML topic: OpenVPN — out-of-bounds write in legacy key-method 1 Related CVEs: CVE-2017-12166 CVE-2017-7478 CVE-2017-7479 CVE-2017-7508 CVE-2017-7512 CVE-2017-7520 CVE-2017-7521 CVE-2017-7522 Upstream summary: Steffan Karger reports: The bounds check in read_key() was performed […]

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Ubuntu 18.04 — flightcrew — multiple vulnerabilities (3 CVEs) — patch and remediation guide — diagnosis and fix on Ubuntu 18.04

Ubuntu 18.04 — flightcrew — multiple vulnerabilities (3 CVEs) — patch and remediation guide

🟡 Medium   ⏱ 10–30 min  Last verified: 6 June 2019 Affected versions: Ubuntu 18.04 (bionic) 📖 ~4 min read  •  Source: Ubuntu Security Notice USN-4055-1 Related CVEs: CVE-2019-13032 CVE-2019-13241 CVE-2019-13453 Upstream summary: Mike Salvatore discovered that FlightCrew improperly handled certain malformed EPUB files. An attacker could potentially use this vulnerability to cause a denial […]

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SLES 15 — libgnomesu — vulnerability — patch and remediation guide — diagnosis and fix on SLES 15

SLES 15 — libgnomesu — vulnerability — patch and remediation guide

🟡 Medium   ⏱ 10–30 min  Last verified: 6 June 2019 Affected versions: SLES 15 📖 ~4 min read  •  Source: SUSE security advisory (see also SUSE bugzilla) Related CVEs: CVE-2011-1946 Upstream summary: gnomesu-pam-backend in libgnomesu 1.0.0 prints an error message but proceeds with the non-error code path upon failure of the setgid or setuid […]

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Debian 9 — mupdf — multiple vulnerabilities (4 CVEs) — patch and remediation guide — diagnosis and fix on Debian 9

Debian 9 — mupdf — multiple vulnerabilities (4 CVEs) — patch and remediation guide

🟡 Medium   ⏱ 10–30 min  Last verified: 6 June 2019 Affected versions: Debian 9 (stretch) 📖 ~4 min read  •  Source: Debian Security Tracker Related CVEs: CVE-2017-14685 CVE-2017-15587 CVE-2017-17866 CVE-2018-6544 Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution – Primary Fix Solution – Alternative Approaches […]

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